Method of preparing for stringing the frame of a games racket



Dec. 22, 19 0 w. c. CARLTON METHOD OF PREPARING FOR STRINGING THE FRAMEOF A GAMES RACKFIT Filed March 27. 1969 IwENwR WILL/RN C- GHRLTWV UnitedStates Patent 3,548,484 METHOD OF PREPARING FOR STRINGING THE FRAME OF AGAMES RACKET William C. Carlton, New Hall, Ardleigh, England, as-

signor to Carlton Sports Company Limited, London, England, a Britishcompany Filed Mar. 27, 1969, Ser. No. 811,100 Claims priority,application Great Britain, Apr. 3, 1968, 15,931/68 Int. Cl. 1323p 17/00U.S. Cl. 29-423 2 Claims ABSTRACT OF THE DISCLOSURE Improved grommetsfor the stringing apertures of badminton, tennis, squash and other gamesrackets are of tubular form having an outwardlyextending flange at oneend and tapered at the other end. Grommets of this form are easilylocated in the stringing apertures of the racket. Nylon 12 and rigidp.v.c. are preferred materials for the grommet which conveniently has anexternal shoulder or step adjacent its tapered end. The grommets areused in a method of preparing a racket for stringing by inserting them,tapered end first, through the stringing apertures of the racket frameand then removing, such as by trimming, at least part of the protrudingtapered ends. The external shoulder feature provides a ready guide as toa suitable amount by which the ends should be trimmed, of which thefollowing is a specification.

This invention relates to tubular grommets for games rackets and to amethod of preparing the frame of a games racket for stringing using suchgrommets.

The invention provides a tubular moulded grommet or insert for a gamesracket, which has an outwardlyextending flange at one end, and istapered at the other end. Grommets of the invention are used inpreparing for stringing the frame of a badminton, tennis, squash orother games racket, having a series of stringing apertures spaced aroundthe head of the frame, in which said grommets are inserted, tapered endfirst, into the apertures, the grommets are pushed firmly intoengagement with the apertures so that the tapered ends protrude beyondthe inside of the head, and then the tapered ends are removed, forinstance by trimming with a knife. Where the tapered end of the grommetis also closed insertion through the apertures in the frame isfacilitated. Preferably, the closed end of the insert is tapered to apoint, although the extremity of the taper may alternatively be rounded.

The grommets of the invention have the following advantages. First, wehave found that if parallel-sided grommets are used their insertion intothe apertures in the frames is frequently time-consuming, especiallywhen the frame is a tubular frame, since the ends of the grommets maycatch on the edges of the frame surrounding the apertures on the insideof the racket frame. Secondly, the inside of the racket frame afterinsertion of the grommets often has an uneven appearance since it isdifficult to ensure that all the grommets project beyond the inside ofthe frame by the same amount.

In a preferred form of the method of the invention the grommet isinserted, tapered end first, into an aperture in the racket frame fromthe outside of the frame, the grommet being of such a length that whenthe flanged end engages on the outside of the frame the tapered endprojects beyond the inside of the frame. The tapered end is subsequentlyremoved so that an open-ended flanged grommet remains, the cut endprojecting sufliciently beyond the inside of the frame to be deformedunder the pressure exerted by the stringing which is subsequently 'iceapplied to the racket frame. Preferably, the exterior of the grommet hasa shoulder positioned so that the shank of the grommet beyond theshoulder corresponds to the portion subsequently to be removed.

In manufacturing the grommets in a mould having a female part and a malepart, the male part can with advantage be provided with an annulargroove into which the moulding material can flow. The effect of thisannular groove during withdrawal of the male part is to withdraw themoulding with said male part from. the female part of the mould. Theinsert can then be removed from the male part much more readily than itcould be if, as is normally the case, it remained in the female part.The annular groove on the male part of the tool causes the Wall of thecorresponding part of the grommet to be thicker than elsewhere. Whilstthis would be undesirable if it were present in the grommet duringstringing, it does not present a problem if it is situated in the partof the grommet which is removed prior to stringing.

The material from which the moulded grommets are made is chosen suchthat it will withstand the tension of the strings without flowing awayfrom them when backed by the material of which the frame is made.Moreover said material is chosen to be strong enough to prevent thetension of the strings from forcing the metal of the racket framethrough the grommet. Preferably the material chosen for the grommetsshould be sufiicient to withstand a tension of lbs. in the case oftennis rackets and a tension of 24 lbs. in the case of badmintonrackets. The grommets are preferably of a material which, after assemblyof the grommets in the apertures of the frame, will permanently deformunder the tension of the strings of the racket. Suitable plasticsmaterials for the grommets are nylon twelve and rigid polyvinylchloride,but the invention is not limited to the use of these particularmaterials.

In order that the invention may be clearly understood and readilycarried into effect it will now be more fully described with referenceto the accompanying drawings, in which:

FIG. 1 is a plan view of a plurality of inserts (grommets) according toone embodiment of the invention, the inserts all being integral, in areadily removable manner, with a common supporting member,

FIG. 2 is a section, on an enlarged scale, through one of the inserts ofFIG. 1, taken on the line IIII, and

FIG. 3 shows in section, and on the same enlarged scale, an insert in anaperture in a racket frame, the end of the insert on the inside of theframe having been cut off.

FIG. 4 shows in section and on the same enlarged scale, as analternative embodiment, an insert with a tapered but not closed end.

In the embodiment shown in FIGS. 1, 2 and 3 of the drawings a pluralityof flanged inserts of plastics material are integrally moulded togetheras shown in FIG. 1. Each insert 1 is of the form shown in FIG. 2, havingat one end an outwardly directed flange 2 and being closed and taperedat the other end 3. In this embodiment the closed end 3 is tapered to apoint, although if desired the extremity of the taper may be radiused.The insert has a small pullout flange 10 which has resulted from agroove in the male portion of the moulding tool. The exterior of theinsert 1 is provided with a shoulder 4 as indicated, near the closed end3. The purpose of the shoulder 4 will be explained more fullyhereinafter.

As shown in FIG. 1 twelve inserts 1 are integrally moulded from asuitable plastics material together with a star shaped supporting member5 having twelve limbs, one for each insert 1. Each limb 6 is integral,via a thinner portion 7, with the flange 2 of the respective insert 1.By way of example the plastics material of the insert 1 and supportingmember may be nylon 12 or rigid polyvinylchloride.

In order to apply the inserts to apertures through a racket frame, aninsert 1 is detached from its respective limb 6 by breaking the thinnerportion 7 and said insert 1 is then inserted, closed end 3 first, intoan aperture through the frame from the outside of the frame until theflange 2 engages the outside surface of the frame around the aperture.The length of the sleeve 1 is arranged to be such that in this positionthe shoulder 4 projects beyond the inside surface of the racket frame,the closed end 3 projecting even further beyond said inside surface.This is repeated for the other apertures through the racket frame andsubsequently the closed ends 3 of the inserts 1 in said apertures areall cut off at the shoulders 4 so that the remaining ends of saidinserts 1 project sufliciently beyond the inside of the racket frame toenable material of said inserts adjacent said cut off ends to bedeformed by stringing which is subsequently applied to the racket frame.

FIG. 3 shows an insert 1 in position in an aperture in a racket frame 8for stringing, the insert 1 having been cut off at its shoulder 4. Inthis particular embodiment the racket frame 8 is formed from a metaltube, the apertures through the tube for the stringing having integralflanges 9 projecting towards the interior of the tube from the insideand the outside of the racket frame. When stringing is applied to theracket frame 8 the end of the insert 1 remote from the flange 2 aftercutting off becomes deformed by said stringing over the respectiveflange 9. Alternatively, if desired said end may be flanged, using asuitable tool, after cutting off but before stringing is applied to theframe.

In some racket frames the lengths of the inserts 1 may be required to bedifferent for different apertures in the racket frame. This may, forexample, be the case when a part of the outside surface of the racketframe is recessed to accommodate stringing between some of theapertures. In this event those apertures which terminate in the recesswill be of smaller depth than other apertures which are provided awayfrom the region of the recess, and different lengths of moulded insertsare preferably employed for the different depths of apertures. Allinserts are then cut off so as to project by substantially the sameamount from the inside of the racket frame.

FIG. 4 shows an insert which is tapered but open ended at 11.

Having now described my invention, What I claim is:

1. A method of preparing for stringing the frame of a games racket saidframe comprising a head having spaced along the length thereof a seriesof stringing apertures, comprising inserting into said apertures,tapered end first, grommets having an elongated tubular portion, aflange extending outwardly from one end of said tubular portion, and atapered extension portion extending from the end of said tubular portionopposite said one end thereof, pushing the grommets firmly intoengagement 1 with the apertures so that said tapered extension portionsprotrude beyond the inside of the head, and then removing at least theends of said tapered extension portions.

2. A method as claimed in claim 1, in which the exterior of the grommethas, in or adjacent said tapered extension portion, a step at whichthere is a substantial change in the Width of the grommet, the width ofthe grommet immediately on that side of the step further from saidflange being less than the width immediately on that side of the stepnearer said flange, and said tapered extension portions are removed bycutting the grommets adjacent said step.

References Cited UNITED STATES PATENTS 1,588,140 6/1926 Penney 27373.81,611,232 12/1926 Reach 27373.8 2,542,661 2/1951 Godfrey 27373.42,550,788 5/1951 De Swart 24141 3,065,004 11/1962 Laich 16-2X 3,290,43012/1966 Klumpp, Jr., et a1 162X FOREIGN PATENTS 546,787 4/1956 Belgium273-73 (4) 269,955 5/ 1927 Great Britain.

JOHN F. CAMPBELL, Primary Examiner R. J. SHORE, Assistant Examiner US.Cl. X.R.

